|Anime debut||Episode 6|
|Seiyū||Atsumi Tanezaki (Japanese)
Leah Clark (English)
Mayu Arita (有田マユ Arita Mayu) is a student who is a huge fan of the idol group C.H.A, of which Harada is a member.
Arita is a fashionable girl with brown eyes and a mole near her lips. She cakes a crazy amount of makeup on her face and paints her nails with pink polish. She ties some of her curly hair in a bun, locking it with a ponytail adorned by a brown blushing teddy bear, and lets the remaining strands flow freely on the sides of her face. Furthermore, she accessorizes herself with earrings, necklace, and a pink scrunchy on her right arm.
For her outfit, she wears a school uniform consisting of a white collar shirt with a blue tie, dark blue short skirt, black socks, and brown shoes.
She’s usually foolish and lighthearted, but has a pure side as well. She is shown to be selfless towards the ones she cares about when she sacrifices herself, thinking this will allow Harada to live.
Ginti makes Mayu and Harada play a game of Twister. While it originally starts out without too many complaints, tension quickly built up when Ginti made it so the colored spaces the players would touch activated extreme weather changes.
Eventually, Ginti drops the floor out from Mayu and Harada. The two start to panic when forced to stay on narrow platforms high above what seemed to be sharp spikes on the ground. Ginti says that the game will end when only one person is left on the suspended platform.
Mayu sacrifices herself and begins to allow herself to fall. Harada, who originally considered pushing her off, catches her by her arm. The two exchange words until Harada can no longer support her weight and Mayu plunges to the ground.The 'spikes' are then revealed to be completely harmless. As she falls, she recalls that she died by tripping on a bar of soap and having fallen on her head, she probably bled to death (via external bleeding or hemorrhaging of the brain), or died via an extreme concussion.
In Episode 11, she was cast into the void alongside the Harada dummy.
- "I pity you arbiters. I decided for myself. Maybe it wasn't a life that others would be proud of, but I'M the one who decided to devote it to Harada."